Someone can please help me ?

[RoAlexu]

i recently wanted to install a car mod in gta , done all the steps , and then realize that the car visuals haven't been changed , i thought it was maybe a mistake i did , and tried to delete the files that i putted in the specific places and when i wanted to start the game again it told me that the game has ''corrupt game data'' , and i can not figure out what should i do , can you guys give e a clue on what i should do in order to get this thing solved ? please and thank you !